Actually , I've only had trouble with cyano
in the tank with live sand, not in my gravel.
Vacuum the gravel regularly
Watch that you are not overfeeding.
feeds on phosphates. I have read that phosphates will be carried out of the system on the surface of air bubbles. My main 30 gal
has always had a bubble curtain ( because the rest of my family like the way it looks) and I have never had a cyano
problem. My daughter's tank did not have a bubble curtain - huge cyano
problem. Got on top of it with chemi-clean - changed the substrate - put in a bubble curtain - no cyano
. Coincidence ? Maybe - but worth thinking about.
And again - chemi-clean works great. It lets you get on top of the problem and regain control, esp if you don't have thte bucks for the skimmers and water units. You can order it on line for about $15 after shipping is added in.
With a 29 gallon tank you migh consider buying water for your changes, but be careful - even bottled water can be high in phosphates. I read somewhere that Wal-Mart water is among the highest in phosphate amount.